"""Tests for CER-016 risk guard."""

from __future__ import annotations

import pytest
from fastapi import HTTPException
from option_mcp_common.risk_guard import (
    enforce_aggregate,
    enforce_leverage,
    enforce_single_notional,
    max_aggregate,
    max_leverage,
    max_notional,
)


def test_defaults(monkeypatch):
    for k in ("CERBERO_MAX_NOTIONAL", "CERBERO_MAX_AGGREGATE", "CERBERO_MAX_LEVERAGE"):
        monkeypatch.delenv(k, raising=False)
    assert max_notional() == 200.0
    assert max_aggregate() == 1000.0
    assert max_leverage() == 3


def test_env_override(monkeypatch):
    monkeypatch.setenv("CERBERO_MAX_NOTIONAL", "50")
    monkeypatch.setenv("CERBERO_MAX_AGGREGATE", "150")
    monkeypatch.setenv("CERBERO_MAX_LEVERAGE", "2")
    assert max_notional() == 50.0
    assert max_aggregate() == 150.0
    assert max_leverage() == 2


def test_leverage_default_when_none(monkeypatch):
    monkeypatch.delenv("CERBERO_MAX_LEVERAGE", raising=False)
    assert enforce_leverage(None) == 3


def test_leverage_accepts_within_cap(monkeypatch):
    monkeypatch.delenv("CERBERO_MAX_LEVERAGE", raising=False)
    assert enforce_leverage(2) == 2
    assert enforce_leverage(3) == 3


def test_leverage_rejects_above_cap(monkeypatch):
    monkeypatch.delenv("CERBERO_MAX_LEVERAGE", raising=False)
    with pytest.raises(HTTPException) as exc:
        enforce_leverage(50)
    assert exc.value.status_code == 403
    assert exc.value.detail["error"] == "HARD_PROHIBITION"


def test_leverage_rejects_below_one(monkeypatch):
    with pytest.raises(HTTPException):
        enforce_leverage(0)


def test_single_notional_ok(monkeypatch):
    monkeypatch.delenv("CERBERO_MAX_NOTIONAL", raising=False)
    enforce_single_notional(100.0, exchange="deribit", instrument="BTC-PERPETUAL")


def test_single_notional_rejects(monkeypatch):
    monkeypatch.delenv("CERBERO_MAX_NOTIONAL", raising=False)
    with pytest.raises(HTTPException) as exc:
        enforce_single_notional(335.0, exchange="hyperliquid", instrument="ETH")
    assert exc.value.status_code == 403
    assert "335" in exc.value.detail["message"]


def test_aggregate_ok(monkeypatch):
    monkeypatch.delenv("CERBERO_MAX_AGGREGATE", raising=False)
    enforce_aggregate(current_total=500.0, new_notional=200.0)


def test_aggregate_rejects(monkeypatch):
    monkeypatch.delenv("CERBERO_MAX_AGGREGATE", raising=False)
    with pytest.raises(HTTPException) as exc:
        enforce_aggregate(current_total=900.0, new_notional=200.0)
    assert exc.value.status_code == 403